863
FXUS63 KMQT 051745
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
145 PM EDT Sat Sep 5 2026

.KEY MESSAGES...

- Patchy dense fog is expected this morning, especially in the
  higher elevations of the central and western U.P.

- Above-average temperatures persist through Labor Day Weekend, with
  high temperatures in the mid 70s to low 80s.

- Dry conditions prevail Saturday and Sunday. Precipitation
  chances increase late on Labor Day, reaching 50% in the far
  west by the evening.

&&

.DISCUSSION...
Issued at 230 AM EDT Sat Sep 5 2026

Early this morning GOES water vapor imagery and 500mb model height
analysis showed an upper level ridge extending from the southern
plains north into the Canadian Prairies, resulting in northwest flow
aloft over the Great Lakes. At the surface troughing extended
through much of the high plains, in the lee of the Rockies with high
pressure over Ontario, resulting in light northeasterly flow over
the U.P. GOES fog and microphysics products showed widespread low
stratus and fog over the western and southern halves of the U.P.
Dense fog had developed in some locations where fog was being
enhanced by upslope flow, such as the higher elevations of Marquette
County. Temperatures were in the upper 50s where skies had cleared
in the east and far north (Keweenaw) with low to mid 60s elsewhere.

Not much change is expected in the pattern today into Sunday with an
overall warm and pleasant Labor Day Weekend expected. Surface high
pressure over Ontario will continue to extend a ridge south into the
U.P. with a weak pressure gradient resulting in light northeasterly
flow. Locally dense fog can be expected to start out the day over
the western and southern halves of the U.P. Did not issue any
headlines for the fog as it seems confined to favored upslope areas
and not widespread. Expect fog and low clouds to diminish through
mid-morning as diurnal heating mixes out the low levels.
Temperatures will warm well into the 70s with abundant sunshine this
afternoon over the north and east though scattered clouds will
linger over parts of the western U.P. With clear skies and light
winds expect good radiational cooling tonight with temperatures
falling into the 40s away from the shorelines. Patchy fog may again
develop tonight (30-50% chance), mainly in the central and eastern
U.P. For the remainder of the Labor Day weekend expect highs in the
upper 70s to low 80s along with partly cloudy skies Sunday, giving
way to increasing cloud cover Monday afternoon as a system
approaches the area.

Precip chances return Monday night from the west, continuing
into Tuesday night as the upper level ridge moves east and
flattens. This gives way to the deep western trough to lift
northeast to Manitoba by the end of the day Tuesday, then
tracking east to Quebec. A resulting sfc low from the northern
Rockies lifts to Manitoba by Tuesday morning, then moves across
far northern Ontario to Quebec through Wednesday. Showers and
storms return to the UP ahead of the associated cold front,
mainly on Tuesday. This does not look to bring much in the way
of strong storms, but it does present the best rainfall chances
as of recent. NBM probabilities of at least 1 inch of rain in 24
hours are between 30-50%. This system also yields breezy winds.
Initially expecting south winds on Tuesday ahead of the cold
front gusting between 15-30 mph, particulary in ideal southerly
downslope flow. Behind the front, pressure rises and CAA support
stronger westerly winds on Wednesday with frequent gusts of
20-30 mph. Probabilities for wind gusts exceeding 40 mph are
between 30-60% in the Keweenaw.

There is a slight chance (15-24% chance) for additional showers late
Wednesday into Thursday with a shortwave to the north and a
secondary cold front pressing south. Otherwise temps return near
normal in the mid 60s to mid 70s late next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 145 PM EDT Sat Sep 5 2026

VFR conditions and light winds prevail through much of the TAF
period under high pressure. Another round of early morning radiation
fog will be the primary aviation hazard at SAW and potentially CMX
before lifting just after sunrise. Confidence is lower regarding fog
development at CMX, but given light easterly upsloping there chance
is low but non-zero.

&&

.MARINE...
Issued at 354 PM EDT Fri Sep 4 2026

Lake Superior: Lingering northeast wind gusts above 20 kts in the
western waters falls below 20 kts this evening with high pressure
building in from the north. This high pressure influence keeps winds
below 20 kts through early Monday afternoon. A more prominent system
lifting to the north of Lake Superior Monday night through mid week
brings a prolonged period of 20 to 30 kt winds. Best chances for
gales to 35 kts (30 to 60% chance) are Wednesday behind the cold
front, supported by pressure rises. There is a low (15 to 25%)
chance for southerly warm air advection gales on Tuesday and a 20 to
40% chance for high end gales (40 kts or higher) near the Keweenaw
on Wednesday. Winds settle below 20 kts by late next week.

Northern Green Bay and northwestern Lake Michigan: Winds generally
remain 15 kts or lower through Labor Day as high pressure slowly
builds overhead. A more prominent system lifting north of the region
early next week increases winds to around 15 kts with gusts up to 20
to 30 kts Tuesday afternoon through Wednesday.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.

&&

$$

DISCUSSION...77/NL
AVIATION...BW
MARINE...77